* {
    /*清除内外边距*/
    margin: 0;
    padding: 0;
}

.container {
    width: 1000px;
    /*设定版心居中对齐*/
    margin: 0 auto;
}

header {
    text-align: center;
    padding-top: 80px;
}

header h1 {
    font-size: 28px;
}

header a {
    display: block;
    width: 120px;
    height: 30px;
    background-color: black;
    margin: 50px auto 20px auto;
    color: #ffffff;
    line-height: 30px;
    text-decoration: none;
    border-radius: 4px;
}

nav {
    font: normal bold 40px "等线";
    color: aliceblue;
    text-align: center;
    padding-top: 2px;
    padding-bottom: 20px;
}

nav a {
    color: rgb(255, 255, 255);
    text-decoration: none;
    font-size: 30px;
    padding: 0 40px;
    font-family: "等线";
    position: relative;
}

.container nav a:hover {
    width: 100px;
    height: 30px;
    border: 3px solid rgb(100, 184, 230);
}

.work {
    width: 800px;
    margin: 10px auto;
    text-align: center;
}

.first {
    vertical-align: top;
}

.second {
    vertical-align: middle;
}

.third {
    vertical-align: bottom;
}

.my {
    width: 150px;
    height: 200px;
}

.first {
    width: 180px;
    height: 200px;
}

.second {
    width: 260px;
    height: 150px;
}

.third {
    width: 180px;
    height: 260px;
}

.o {
    padding-bottom: 20px;
}

.t {
    padding-bottom: 15px;
    margin-right: px;
}

.t .second {
    padding-top: 30px;
    padding-left: 50px;
    padding-right: 50px;
    padding-bottom: 30px;
}

.h .third {
    padding-top: 20px;
    padding-left: 10px;
    padding-bottom: 150px;
}